Medical instruments and techniques for treating pulmonary disorders

ABSTRACT

A surgical instrument for delivering energy to lung tissue, for example to cause lung volume reduction. In one embodiment, an elongated catheter has a handle portion that includes an interior chamber that is supplied with a biocompatible liquid media under pressure. An energy source delivers energy to the media to cause a liquid-to-vapor phase change within the interior chamber and ejects a flow of vapor media from the working end of the catheter. The delivery of energy and the flow of vapor are controlled by a computer controller to cause a selected pressure and selected volume of vapor to propagate to the extremities of the airways. Contemporaneously, the vapor undergoes a vapor-to-liquid phase transition which delivers a large amount of energy to airway tissue. The thermal energy delivered is equivalent to the heat of vaporization of the fluid media, which shrinks and collapses the treated airways. The treated tissue is the maintained in a collapsed state by means of aspiration for a short interval to enhance tissue remodeling. Thereafter, the patient&#39;s wound healing response causes fibrosis and further remodeling to cause permanent lung volume reduction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Patent ApplicationNo. 60/615,900 filed Oct. 5, 2004 titled Medical Instruments andTechniques for Thermally-Mediated Procedures. This application is also acontinuation-in-part of U.S. patent application Ser. No. 10/346,877filed Jan. 18, 2003 now U.S. Pat. No. 6,911,028 titled MedicalInstrument Working End and Method for Endoluminal Treatment, the entirecontents of which is incorporated herein by this reference and should beconsidered a part of this specification. This application is also acontinuation-in-part application of U.S. application Ser. No.10/681,625, filed Oct. 7, 2003 now U.S. Pat. No. 7,674,259.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to methods and systems forapplying energy to tissue, and more particularly to methods and systemsfor injecting vapor media into an airway and causing a vapor-to-liquidphase state change to thereby apply thermal energy equivalent to theheat of vaporization of the vapor media into the lung. The delivery ofenergy is accomplished with a catheter in a minimally invasive procedureto shrink, seal and ablate a targeted region to reduce the effectivevolume of a patient's lung.

2. Description of the Related Art

Emphysema is a debilitating illness brought about by the destruction oflung tissue. The disorder affects up to 10% of the population over 50years old. Emphysema is most commonly caused by cigarette smoking and,in some cases, by a genetic deficiency. The condition is characterizedby abnormalities of the alveoli, which are the microscopic air sacs inthe lung where gas exchange takes place. Destruction of these air sacsmakes it difficult for the body to obtain oxygen and to get rid ofcarbon dioxide.

In emphysema, there is a progressive decline in respiratory function dueto a loss of lung elastic recoil with a decrease of expiratory flowrates. The damage to the microscopic air sacs of the lung results inair-trapping and hyperinflation of the lungs. As the damaged air sacsenlarge, they push on the diaphragm making it more difficult to breathe.The enlarged air sacs also exert compressive forces on undamaged lungtissues, which further reduces gas exchange by the undamaged lungportions. These changes produce the major symptom emphysema patientssuffer—dyspnea (shortness of breath) and difficulty of expiration.Current pharmacological treatments for emphysema include bronchodilatorsto improve airflow. Also, oxygen therapy is used for patients withchronic hypoxemia.

More recently, a surgical procedure called lung volume reduction (LVR)has been developed to alleviate symptoms of advanced chronic obstructivelung disease that results from emphysema. This surgical resection isvariably referred to as lung reduction surgery or reduction pneumoplastyin which the most severely emphysematous lung tissue is resected.

The development of LVR was based on the observation that emphysemacauses the diseased lung to expand and compress the normally functioninglung tissue. If the diseased lung tissue were removed, it was believedthat the additional space in the chest cavity would allow the normallung tissue to expand and carry on gas exchange. LVR was firstintroduced in the 1950's but was initially abandoned due to a highoperative mortality, primarily due to air leakage. One of the maindifficulties of the procedure is suturing the resected lung margin in anairtight manner. Normally there is a vacuum between the ribs and thelungs that helps to make the lungs expand and fill with air when thechest wall expands. If an air leak allows air in the potential spacebetween the ribs and lungs—then the vacuum effect will disappear and thelungs will sag upon chest expansion making it increasingly difficult toinflate the lungs and perform gas exchange.

Currently, there are two principal surgical approaches for LVR—both ofwhich involve removal of diseased lung tissue (typically in the upperlobes) followed by surgical stapling of the remaining lung to close upthe incision. One approach is an open surgery in which the surgeon usesa median sternotomy to access the chest cavity for removal of diseasedlung tissue. The second approach is a video-assisted thoracic surgery inwhich endoscopic instruments are inserted into the chest cavity throughsmall incisions made on either side of the chest. LVR downsizes thelungs by resecting badly diseased emphysematous tissue that isfunctionally useless. Surgeons generally remove approximately 20-30% ofeach lung in a manner that takes advantage of the heterogeneity ofemphysema in which the lesions are usually more severe at the apices andless severe at the lung bases. During the course of surgery, one lung iscontinually ventilated while the lumen of the contralateral lung isclamped. Subsequently, normal areas of the lung deflate as blood flowspast the alveoli and resorbs oxygen, while emphysematous portions of thelung with less blood flow and reduced surface area remain inflated andare targeted for resection. The more recent procedures use bovinepericardium or other biocompatible films to buttress a staple line alongthe resected lung margin to minimize air leaks.

LVR improves function of the lung by restoring pulmonary elastic recoiland correcting over-distention of the thorax and depression of thediaphragm. Thus, the objective of LVR is to provide the patient withimproved respiratory mechanics and relief from severe shortness ofbreath upon exertion. Many patients have reported benefits such asimproved airflow, increased functional lung capacity and an improvedquality of life. As in any major thoracic procedure, there are manyrisks, including fever, wound infections, wound hematomas, postoperativefatigue and tachycardia. The recuperation period following LVR variesfrom person to person, but most patients remain in the hospital for twoweeks following surgery. The patient then must endure a regime ofphysical therapy and rehabilitation for several additional months.Further, the duration of the improvement in lung function followingresection is not yet completely known—but there is a suggestion thatlung function begins to decline two years after LVR. Despite optimisticreports, the morbidity, mortality and financial costs associated withLVR appear to be high, with some studies indicating mortality ratesranging from 4 to 17%.

SUMMARY OF THE INVENTION

In general, a method corresponding to the invention comprises causing avapor-to-liquid phase state change in a selected media in targetedairways of a patient's lung thereby applying thermal energysubstantially equal to the heat of vaporization of the lung.Endothelial-lined structures of the body, such as airways, havesubstantially collagen cores. Intermolecular cross-links providecollagen connective tissue with unique physical properties such as hightensile strength and substantial elasticity. A well-recognized propertyof collagen relates to the shrinkage of collagen fibers when elevated intemperature to the range 60° to 80° C. Temperature elevation rupturesthe collagen ultrastructural stabilizing cross-links, and results inimmediate contraction in the fibers to about one-third of their originallongitudinal dimension. Thus, the method of the invention includesdelivering thermal energy within the sufficient to collapse and shrinktargeted portions of a bronchial tree.

A preferred method delivers large amounts of energy to lung tissue by avapor-to-liquid phase transition or “internal energy” release from abiocompatible vapor such as saline. FIGS. 1A and 1B illustrate thephenomena of phase transitional releases of internal energies. Suchinternal energy involves energy on the molecular and atomic scale—and inpolyatomic gases is directly related to intermolecular attractiveforces, as well as rotational and vibrational kinetic energy. In otherwords, the method of the invention exploits the phenomenon of internalenergy transitions between gaseous and liquid phases that involve verylarge amounts of energy—that can be released to apply energy to bodystructure.

It has been found that the controlled application of internal energiesin an introduced media-tissue interaction solves many of the vexingproblems associated with energy-tissue interactions in conventional Rf,laser, microwave and ultrasound modalities. The apparatus of theinvention provides a fluid-carrying chamber in the interior of thedevice or working end. A source provides liquid media to the interiorchamber wherein energy is applied to instantly vaporize the media. Inthe process of the liquid-to-vapor phase transition of a saline media inthe interior of the working end, large amounts of energy are added toovercome the cohesive forces between molecules in the liquid, and anadditional amount of energy is requires to expand the liquid 1000+percent (PΔD) into a resulting vapor phase (see FIG. 1A). Conversely, inthe vapor-to-liquid transition, such energy will be released at thephase transitions at the targeted tissue interface. That is, the heat ofvaporization is released in tissue when the media transitioning fromgaseous phase to liquid phase wherein the random, disordered motion ofmolecules in the vapor regain cohesion to convert to a liquid media.This release of energy (defined as the capacity for doing work) relatingto intermolecular attractive forces is transformed into therapeutic heatfor a thermotherapy within a targeted body structure. Heat flow and workare both ways of transferring energy.

In FIG. 1A, the simplified visualization of internal energy is usefulfor understanding phase transition phenomena that involve internalenergy transitions between liquid and vapor phases. If heat were addedat a constant rate in FIG. 1A (graphically represented as 5 calories/gmblocks) to elevate the temperature of water through its phase change toa vapor phase, the additional energy required to achieve the phasechange (latent heat of vaporization) is represented by the large numberof 110+ blocks of energy at 100° C. in FIG. 1A. Still referring to FIG.1A, it can be easily understood that all other prior art ablationmodalities—Rf, laser, microwave and ultrasound—create energy densitiesby simply ramping up calories/gm as indicated by the temperature rangefrom 37° C. through 100° C. as in FIG. 1A. The prior art modalities makeno use of the phenomenon of phase transition energies as depicted inFIG. 1A.

FIG. 1B graphically represents a block diagram relating to energydelivery aspects of the present invention. The system provides forinsulative containment of an initial primary energy-media within aninterior chamber of an instrument's working end. The initial, ascendantenergy-media interaction delivers energy sufficient to achieve the heatof vaporization of a selected liquid media such as saline within aninterior of the instrument body. This aspect of the technology requiresan inventive energy source and controller—since energy application fromthe source to the selected media (Rf, laser, microwave, ultrasound,inductive heating, etc.) must be modulated between very large energydensities to initially surpass the latent heat of vaporization of themedia within milliseconds, and possible subsequent lesser energydensities for maintaining the media in its vapor phase. Additionally,the energy delivery system is coupled to a pressure control system forreplenishing the selected liquid phase media at the required rate—andoptionally for controlling propagation velocity of the vapor phase mediafrom the working end surface of the instrument. In use, the method ofthe invention comprises the controlled deposition of a large amount ofenergy—the heat of vaporization (sometimes referred to as release ofheat of condensation) as in FIG. 1A—when the vapor-to-liquid phasetransition is controlled at the vapor media-tissue interface. Thevapor-to-liquid phase transition deposits about 580 cal/gram within thetargeted tissue site to perform the thermal ablation.

In general, the system of the invention is adapted to provide leastinvasive methods for lung volume reduction that are accomplished byusing thermal energy to treat and shrink targeted regions of a thebronchial. In one embodiment, an elongated catheter is configured forintroduction in a targeted airway. The handle portion of the catheterincludes an interior chamber that is supplied with a biocompatibleliquid under pressure. An energy source is coupled to the interiorchamber to cause a liquid-to-vapor phase change in the biocompatibleliquid, which contemporaneously ejects a flow of vapor from the workingend of the catheter. The flow of vapor is controlled by a controller tocause a selected pressure and selected volume of vapor to propagate toalveoli. The vapor flow instantly undergoes a vapor-to-liquid phasechange to thereby applying energy to the airway tissue. The thermalenergy delivered is equivalent to the heat of vaporization of the fluidmedia, which shrinks and collapses the treated airways that are notsupported by substantial cartilage. The treated tissue is maintained ina collapsed state by means of aspiration for a short interval to enhancetissue remodeling. Thereafter, the patient's wound healing response willcause fibrosis and further remodeling of the treated airway tissue tocause lung volume reduction.

The invention provides a method for LVR that can eliminate thecomplications of open surgery, endoscopic surgery or various bronchialplugs.

The invention provides a method for LVR that does not requiretransection of the exterior lung wall thus eliminating the seriouscomplications of air leakage into the chest cavity.

The invention provides a method for LVR that can greatly reduce thepatient's recuperative period and hospital stay.

The invention provides a method for LVR that can be repeated over apatient's lifetime.

The invention provides a method for LVR that will allow for greatlyreduced costs when compared to open or endoscopic LVR procedures.

Additional advantages of the invention will be apparent from thefollowing description, the accompanying drawings and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a graphical depiction of the quantity of energy needed toachieve the heat of vaporization of water.

FIG. 1B is a diagram of phase change energy release that underlies onemethod of the invention.

FIG. 2A is a perspective view of the working end of an exemplary Type“A” probe of the present invention with an openable-closeable tissueengaging structure in a first open position.

FIG. 2B is a perspective view similar to FIG. 2A probe of the presentinvention in a second closed position.

FIG. 3 is a cut-away view of the working end of FIGS. 2A-2B.

FIG. 4 is a perspective view of the working end of FIG. 3 capturing anexemplary tissue volume.

FIGS. 5-6 are sectional schematic views of working end of FIG. 3depicting, in sequence, the steps of a method of the present inventionto seal or weld a targeted tissue volume, FIG. 5 illustrating thepressurized delivery of a liquid media to an interior channel, and FIG.6 depicting an electrical discharge that causes a liquid-to-gas phasechange as well as the ejection of the vapor media into the targetedtissue to thermally seal engaged tissue.

FIG. 7 a view of a Type “B” system of the invention with catheterworking end configured for delivery of vapor to airway tissue to treat alung disorder.

FIG. 8 is a cut-away view of the catheter handle of FIG. 7 depicting athermal energy delivery mechanism for the liquid-to-vapor conversion ofa pressurized inflow of a saline solution.

FIG. 9 is a schematic view of the use of the catheter of FIG. 7 intreating lung tissue for lung volume reduction.

FIG. 10 is a sectional view of the catheter sleeve of FIG. 7.

FIG. 11 is a perspective view of the working end of the catheter of FIG.7.

FIG. 12 is a perspective view of an alternative working endcorresponding to the invention with at least one electrode for couplingelectrical energy to vapor ejected from the working end.

FIG. 13 is a cut-away view of an alternative catheter handle with asecondary source of an inflow media for reducing the mass averagetemperature of the ejected vapor.

FIG. 14 is a cut-away view of an alternative catheter handle thatutilizes a resistive heating structure together with a recirculationchannel causing the liquid-to-vapor conversion of a pressurized inflowof a selected inflow media.

DETAILED DESCRIPTION OF THE INVENTION

1. Type “A” Thermotherapy Instrument. Referring to FIGS. 2A, 2B and 3,the working end 10 of a Type “A” system 5 of the present invention isshown that is adapted for endoscopic procedures in which a tissue volumeT targeted for treatment (a thermoplasty) can be captured by a loopstructure. The working end 10 comprises a body 11 of insulator material(see FIG. 3) coupled to the distal end of introducer member 12 extendingalong axis 15. In this exemplary embodiment, the working end 10 has agenerally cylindrical cross-section and is made of any suitable materialsuch as plastic, ceramic, glass, metal or a combination thereof. Theworking end 10 is substantially small in diameter (e.g., 2 mm to 5 mm)and in this embodiment is coupled to an elongate flexible introducermember 12 to cooperate with a working channel in an endoscope.Alternatively, the working end 10 may be coupled to a rigid shaft memberhaving a suitable 1 mm to 5 mm or larger diameter to cooperate with atrocar sleeve for use in endoscopic or microsurgical procedures. Aproximal handle portion 14 of the instrument indicated by the blockdiagram of FIG. 2A carries the various actuator mechanisms known in theart for actuating components of the instrument.

In FIGS. 2A, 2B and 3, it can be seen that the working end 10 carries anopenable and closeable structure for capturing tissue between a firsttissue-engaging surface 20A and a second tissue-engaging surface 20B. Inthis exemplary embodiment, the working end 10 and first tissue-engagingsurface 20A comprises a non-moving component indicated at 22A that isdefined by the exposed distal end of body 11 of working end 10. Thesecond tissue-engaging surface 20B is carried in a moving component thatcomprises a flexible loop structure indicated at 22B.

The second moving component or flexible loop 22B is actuatable by aslidable portion 24 a of the loop that extends through a slot 25 in theworking end to an actuator in the handle portion 14 as is known in theart (see FIG. 3). The other end 24 b of the loop structure 22B is fixedin body 11. While such an in-line (or axial) flexible slidable member ispreferred as the tissue-capturing mechanism for a small diameterflexible catheter-type instrument, it should be appreciated that anyopenable and closable jaw structure known in the art falls within thescope of the invention, including forms of paired jaws with cam-surfaceactuation or conventional pin-type hinges and actuator mechanisms. FIG.2A illustrates the first and second tissue-engaging surfaces 20A and 20Bin a first spaced apart or open position. FIG. 2B shows the first andsecond surfaces 20A and 20B moved toward a second closed position.

Now turning to the fluid-to-gas energy delivery means of the invention,referring to FIG. 3, it can be seen that the insulated or non-conductivebody 11 of working end 10 carries an interior chamber indicated at 30communicating with lumen 33 that are together adapted for delivery andtransient confinement of a fluid media M that flows into chamber 30. Thechamber 30 communicates via lumen 33 with a fluid media source 35 thatmay be remote from the device, or a fluid reservoir (coupled to a remotepressure source) carried within introducer 12 or carried within a handleportion 14. The term fluid or flowable media source 35 is defined toinclude a positive pressure inflow system which preferably is anysuitable high pressure pump means known in the art. The fluid deliverylumen 33 transitions to chamber 30 at proximal end portion 34 a thereof.The distal end portion 34 b of chamber 30 has a reduced cross-sectionthat functions to direct vapor media through a small outlet or nozzleindicated at 38.

Of particular interest, still referring to FIG. 3, paired spaced apartelectrode elements 40A and 40B are exposed in surface 42 of interiorfluid confinement chamber 30. In this exemplary embodiment, theelectrode elements 40A and 40B comprise circumferential exposed surfacesof a conductive material positioned at opposing proximal and distal endsof interior chamber 30, but other arrangements are possible. Theinvention can utilize any suitable configuration of spaced apartelectrodes (e.g., such as concentric electrode surfaces, intertwinedhelical electrode surfaces, adjustable spaced apart surfaces, or porouselectrodes) about at least one confinement chamber 30 or lumen portionof the system. Alternatively, each electrode can comprise one or moreprojecting elements that project into the chamber. The exemplaryembodiment of FIG. 3 shows an elongate chamber having an axial dimensionindicated at A and diameter or cross-section indicated at B. The axialdimension may range from about 0.1 mm to 20.0 mm and may be singular orplural as described below. The diameter B may range from microndimensions (e.g., 0.5 μm) for miniaturized instruments to a largerdimension (e.g., 5.0 mm) for larger instruments for causing thethermally induced liquid-to-vapor transformation required to enable thenovel phase change energy-tissue interaction of the invention. Theelectrodes are of any suitable material such as stainless steel,aluminum, nickel titanium, platinum, gold, or copper. Each electrodesurface preferably has a toothed surface texture indicated at 43 thatincludes hatching, projecting elements or surface asperities for betterdelivering high energy densities in the fluid proximate to theelectrode. The electrical current to the working end 10 may be switchedon and off by a foot pedal or any other suitable means such as a switchin handle 14.

FIG. 3 further shows that a preferred shape is formed into thetissue-engaging surface 20A to better perform the method of fusingtissue. As can be seen in FIGS. 2B and 3, the first tissue-engagingsurface 20A is generally concave so as to be adapted to receive agreater tissue volume in the central portion of surface 20A. The secondtissue-engaging surface 20B is flexible and naturally will be concave inthe distal or opposite direction when tissue is engaged between surfaces20A and 20B. This preferred shape structure allows for controllablecompression of the thick targeted tissue volumes T centrally exposed tothe energy delivery means and helps prevent conductance of thermaleffects to collateral tissue regions CT (see FIG. 4) and as will bedescribed in greater detail below.

FIGS. 2A and 3 show that first tissue-engaging surface 20A defines anopen structure of at least one aperture or passageway indicated at 45that allows vapor to pass therethrough. The apertures 45 may have anycross-sectional shape and linear or angular route through surface 20Awith a sectional dimension C in this embodiment ranging upwards frommicron dimensions (e.g., 0.5 μm) to about 2.0 mm in a large surface 20A.The exemplary embodiment of FIG. 3 has an expanding cross-sectiontransition chamber 47 proximate to the aperture grid that transitionsbetween the distal end 34 b of chamber 30 and the apertures 45. However,it should be appreciated that such a transition chamber 47 is optionaland the terminal portion of chamber 30 may directly exit into aplurality of passageways that each communicate with an aperture 45 inthe grid of the first engaging surface 20A. In a preferred embodiment,the second tissue-engaging surface 20B defines (optionally) a grid ofapertures indicated at 50 that pass through the loop 22B. Theseapertures 50 may be any suitable dimension (cf. apertures 45) and areadapted to generally oppose the first tissue-engaging surface 20A whenthe surfaces 20A and 20B are in the second closed position, as shown inFIG. 2B.

The electrodes 40A and 40B of working end 10 have opposing polaritiesand are coupled to Rf generator or electrical source 55. FIG. 3 showscurrent-carrying wire leads 58 a and 58 b that are coupled to electrodes40A and 40B and extend to electrical source 55 and controller 60. In apreferred embodiment of the invention, either tissue-engaging surfaceoptionally includes a sensor 62 (or sensor array) that is in contactwith the targeted tissue surface (see FIG. 2A). Such a sensor, forexample a thermocouple known in the art, can measure temperature at thesurface of the captured tissue. The sensor is coupled to controller 60by a lead (not shown) and can be used to modulate or terminate powerdelivery as will be described next in the method of the invention.

Operation and use of the working end of FIGS. 2A, 2B and 3 in performinga method of treating tissue can be briefly described as follows, forexample in an endoscopic polyp removal procedure. As can be understoodfrom FIG. 4, the working end 10 is carried by an elongate catheter-typemember 12 that is introduced through a working channel 70 of anendoscope 72 to a working space. In this case, the tissue T targeted forsealing is a medial portion 78 of a polyp 80 in a colon 82. It can beeasily understood that the slidable movement of the loop member 22B cancapture the polyp 80 in the device as shown in FIG. 4 after beinglassoed. The objective of the tissue treatment is to seal the medialportion of the polyp with the inventive thermotherapy. Thereafter,utilize a separate cutting instrument is used to cut through the sealedportion, and the excised polyp is retrieved for biopsy purposes.

Now turning to FIGS. 5 and 6, two sequential schematic views of theworking end engaging tissue T are provided to illustrate theenergy-tissue interaction caused by the method of the invention. FIG. 5depicts an initial step of the method wherein the operator sends asignal to the controller 60 to delivery fluid media M (e.g., salinesolution or sterile water) through lumen 33 into chamber 30. FIG. 6depicts the next step of the method wherein the controller delivers anintense discharge of electrical energy to the paired electrode elements40A and 40B within chamber 30 indicated by electric arc or electricfield EF. The electrical discharge provides energy exceeding the heat ofvaporization of the contained fluid volume. The explosive vaporizationof fluid media M (of FIG. 5) into a vapor or gas media is indicated atM′ in FIG. 6. The greatly increased volume of gas media M′ results inthe gas being ejected from chamber 30 at high velocity through apertures45 of surface 20A into the targeted tissue T. The liquid-to-vaportransition caused by the electrical discharge results in the vapor mediaM′ having a temperature of 100° C. or more as well as carrying the heatof vaporization to deliver thermal effects into or through the targetedtissue T, as indicated graphically by the shaded regions of gas flow inFIG. 6. The fluid source and its pressure mechanism can provide anydesired level of vapor ejection pressure. Depending on the character ofthe introduced liquid media, the media is altered from a first lessertemperature to a second greater temperature in the range of 100° C. orhigher depending on pressure. The ejection of vapor media M′ and itscondensation will uniformly and very rapidly elevate the temperature ofthe engaged tissue to the desired range of about 65° C. to 100° C. tocause hydrothermal denaturation of proteins in the tissue, and to causeoptimal fluid inter-mixing of tissue constituents that will result in aneffective seal. In effect, the vapor-to-liquid phase transition of theejected media M′ will deposit heat equal to the heat of vaporization(also sometimes called the heat of condensation) in the tissue. At thesame time, as the heat of vaporization of media M′ is absorbed by waterin the targeted tissue, the media converts back to a liquid thushydrating the targeted tissue T. Such protein denaturation byhydrothermal effects differentiates this method of tissue sealing orfusion from all other forms of energy delivery, such as radiofrequencyenergy delivery. All other forms of energy delivery vaporize intra- andextracellular fluids and cause tissue desiccation, dehydration orcharring which is undesirable for the intermixing of denatured tissueconstituents into a proteinaceous amalgam.

The above electrical energy deliver step is continuous or can berepeated at a high repetition rate to cause a pulsed form of thermalenergy delivery in the engaged tissue. The fluid media M inflow may becontinuous or pulsed to substantially fill chamber 30 before anelectrical discharge is caused therein. The repetition rate ofelectrical discharges may be from about 1 Hz to 1000 Hz. Morepreferably, the repetition rate is from about 10 Hz to 200 Hz. Theselected repetition rate preferably provides an interval betweenelectrical discharges that allows for thermal relaxation of tissue, thatmay range from about 10 ms to 500 ms. The electrical source or voltagesource 55 may provide a voltage ranging between about 20 volts and10,000 volts to cause instant vaporization of the volume of fluid mediaM captured between the electrode elements 40A and 40B. After a selectedtime interval of such energy application to tissue T, that may rangefrom about 1 second to 30 seconds, and preferably from about 5 to 20seconds, the engaged tissue will be contain a core region in which thetissue constituents are denatured and intermixed under relatively highcompression between surfaces 20A and 20B. Upon disengagement and coolingof the targeted tissue T, the treated tissue will be fused or welded.Over time, the body's wound healing response will reconstitute thetreated tissue by means of fibrosis to create a collagenous volume orscar-like tissue.

2. Type “B” Thermotherapy Instrument. Now referring to FIGS. 7 and 8,another embodiment of vapor generation and delivery system 200 is shown.In the previous embodiment, the working end was optimized for engagingand sealing tissue with a working surface that is in contact withtissue. In the embodiment of FIGS. 7 and 8, the working end is adaptedfor controlled application of energy by means of a vapor-to-liquid phasechange energy release in an endoluminal application such as lung volumereduction or other treatments of airways.

In FIG. 7, it can be seen that system 200 includes a catheter handleportion 202 that transitions into an elongate catheter sleeve 205 thathas an elongated dimension for introduction through a patient's airways,for example through the patient's oral or nasal cavities, to reach thelungs. The diameter of catheter sleeve 205 can range from about 2 Fr. to6 Fr. or more. In a preferred embodiment, the catheter sleeve isconfigured for introduction through the working channel 208 of abronchoscope indicated at 210 in FIG. 9. The catheter sleeve 205 alsocan be introduced in parallel with a bronchoscope, or a larger diametercatheter sleeve 205 can be provided a working channel to accommodate ascope.

The catheter sleeve 205 as shown in FIG. 7 has a outflow lumen orchannel 212 extending from handle 202 for carrying vapor that isgenerated in the handle to working end 215 and the distal outlet 218that is the termination of channel 212 (see FIG. 11). As can be seen inFIGS. 7, 9 and 11, the working end 215 carries a balloon 220 that can beexpanded by means of inflation source 222 coupled to another lumen 223in catheter sleeve 205 (see FIGS. 7 and 10). The balloon can befabricated of any high temperature resistant polymer known in that art.

In preferred embodiments, the catheter sleeve 205 is fabricated of asingle polymeric material or a combination of polymer layers 224 a and224 b (FIG. 10). The exterior layer can have reinforcing in the form ofbraiding as is known in the art. In the embodiment of FIG. 10, theinterior layer 224 a is of a material having a low thermal conductivity,for example less than about 1.0 W/m-K, and preferably less than about0.50 W/m-K. In one example, an unreinforced polyetheretherketone (PEEK)has a thermal conductivity of about 0.25 W/m-K and can be used for atleast inner layer 224 a of the catheter sleeve 205 (FIG. 10). PEEK ishigh temperature resistant engineered thermoplastic with excellentchemical and fatigue resistance plus thermal stability. PEEK had amaximum continuous working temperature of 480° F. and retains itsmechanical properties up to 570° F. in high-pressure environments. Othermaterials used in the catheter can comprise formulations or blends ofpolymers that include, but are not limited to PTFE, polyethyleneterephthalate (PET), or PEBAX. PTFE (polytetrafluoroethylene) is afluoropolymer which has high thermal stability (up to 260° C.), ischemically inert, has a very low dielectric constant, a very low surfacefriction and is inherently flame retardant. A range of homo andco-fluoropolymers are commercialized under such names as Teflon®,Tefzel®, Neoflon®, Polyflon® and Hyflon®. In another embodiment, thecatheter sleeve can carry another layer or structure 224 c of anysuitable thickness intermediate the inner and outer layers 224 a and 224b that comprises a low thermal conductivity layer. Such a layer cancomprise of air gaps, insulative ceramic or glass microspheres orfibers, or at least one lumen that carries a cryofluid in communicationwith a cryogenic fluid source as in known in the art (see FIG. 10).

Now turning to FIG. 8, the cut-away view of handle 202 shows that aninterior chamber 225 is formed within the interior of an insulatormaterial indicated at 228 such as a ceramic or a combination ofmaterials to insulate the interior chamber 225 from the surface of thehandle. An inflow channel 230 communicates with pressurized inflowsource 240 of fluid or liquid media via flexible tube 242 coupled tofitting 244. A computer controller 245 is provided to control parametersof fluid inflows to the interior chamber 225. The interior chamber 225has a distal region in which media flows transition to outflow channel212 that extends to the working end 215. In FIG. 8, it can be seen thatRf source 250 (also operatively connected to controller 245) has firstpolarity (+) lead 252 a and opposing second polarity (−) lead 252 b thatare coupled respectively to first and second conductive surfaces orelectrodes 255A and 255B exposed in interior chamber 225 that serve as athermal energy delivery mechanism. The first conductive surface 255A isthe outer surface of elongated sleeve 256 with bore 258 therein havingdiffuser ports 260 in the sleeve wall for introducing pressurized liquidmedia M into the interior chamber 225. The diffuser ports 260 have asuitable dimension and configuration for diffusing or atomizing a highpressure inflow of flow media M from source 240, which preferably is asaline solution. The second polarity (−) lead is coupled to conductivesurface 255B which comprises a radially outward surface of interiorchamber 225. In the embodiment shown in FIG. 8, it can be seen that thefirst and second conductive surfaces 255A and 255B are concentric,extend over a substantial length of the handle and have a large surfacearea with a fixed spaced apart radial dimension indicated at 262. Theradial dimension 262 between the electrode surfaces is selected to matchthe particular impedance and other operating characteristics of the Rfgenerator.

Referring to FIG. 8, in a method of operation, the system injects avolume liquid saline flow media M at a selected rate under pressure fromsource 240 which is diffused and atomized by ports 260 as the mediaenters interior chamber 225. Contemporaneous with injection anddiffusion of the volume of saline, the system delivers sufficientcurrent from source 250 and controller 245 to the conductive atomizedsaline via the opposing polarity surfaces 255A and 250B which instantlyvaporize the H₂O in the flow media M to generate a vapor M′ that isinjected from interior chamber 225 into lumen or channel 212 of cathetersleeve 205. The instantaneous increase in volume of media in theliquid-to-vapor phase transition greatly increases interior pressures ininterior chamber 225 to thereby accelerate the flow into and through thecatheter sleeve to working end 215. As shown in FIG. 8, the system andhandle can include an optional pressure relief valve schematicallyindicated at 264 so that any overpressures in the interior chamber arereleased. The release of any overpressure can be vented through anadditional lumen in the supply tube 242 or to another chamber in thehandle.

As can be seen in FIGS. 7 and 9, the system further includes aninflation source 222 for inflating balloon 220. The balloon can beinflated with a gas or liquid from a syringe that can be attached toLuer fitting 272 that is in communication with lumen 223 in cathetersleeve 205 that extends to the inflation chamber of balloon 220.

Referring to FIGS. 8 and 9, the system further includes a negativepressure source 270 that communicates with another lumen 273 in cathetersleeve 205 that has an open distal termination 274 in a end portion ofsleeve 205 distal to the expandable balloon (FIG. 11). The handle 202further has a suitable channel indicated at 276 that extends between thenegative pressure source 270 and aspiration lumen 273 in cathetersleeve. It should be appreciated that lumen 273 in catheter sleeve canalso merge into the vapor delivery lumen 212 and still accomplish themethod of the invention, it is preferred to have separate lumens thatextend to the separate terminations in working end 215. As will bedescribed below, lung volume reduction treatments benefit fromapplication of suction or aspiration pressures that are controlled bycontroller 245.

FIG. 9 further depicts a method of the invention in treating a patient'slung for lung volume reduction. A bronchoscope 210 is shown withcatheter sleeve 205 inserted through the working channel 208. The scopecan be inserted through the patient's mouth or nasal passageway. Thepatient can be in an upright or supine position. Depending on whetherthe left or right lung is being treated, and whether the targeted lungportion is near the patient's heart, the patient's position may beadjusted to limit contact between the targeted lobe and the heart. InFIG. 9, it can be seen that the physician has navigated the working end215 to the targeted region 275 of an airway 280 and actuated inflationsource 222 to expand balloon 220 to occlude the airway. The deploymentof balloon 220 is accomplished after viewing and selected the targetedairway region by means of the bronchoscope. The expanded balloon 220will then direct all inflowing vapor in selected directions and towardthe extremities of airway 280.

In a next step, based on a calculation of the volume of the bronchialtree 275 targeted for reduction, the physician sets the pressure, volumeof vapor and rate of vapor delivery in the fluid inflow controller 245that is operatively coupled to the fluid source 240, Rf source 250 andnegative pressure source 270. The physician further selects the powerlevel and duration of the Rf energy delivery at controller 245 tocooperate with the selected volume of inflowing media M. Next, thephysician actuates the negative pressure or aspiration source 270 thatcommunicates with lumen 273 in catheter sleeve 205 which extracts airfrom the targeted lung region 275 that is distal to occlusion balloon220. The extraction of air can collapse the distal portion of thetargeted lung region and better prepare the region for receiving theselected volume of vapor. The extraction of air can be accomplished overa selected aspiration interval ranging from about 10 seconds to 2minutes or more. An optional pressure sensor 285 a located at the distalend of the catheter 205 (FIG. 11) can be used to assist in determiningwhen to terminate aspiration forces. MEMS-fabricated pressure sensorsare known in the art and can be carried in the surface of the catheteror the balloon surface, for example, of the type fabricated byIntegrated Sensing Systems, Inc., 391 Airport Industrial Drive,Ypsilanti, Mich. 48198. Such sensor can be linked back to controller 245to adjust aspiration pressures or to trigger the next step of themethod. The handle 202 can further carry an open-close valve (not shown)in the inflow lumen 212 that can be closed by controller 245 to preventnegative pressure from being applied to the interior chamber 225 orinflow supply tube 242.

The next step of the method of the invention includes termination ofstep of applying aspiration forces and causing controller 245 tocontemporaneously actuate pressurized inflow source 240 and Rf source250 to thereby inject liquid saline media M into interior chamber 225,cause a contemporaneous saline-to-vapor transition, and acontemporaneous pressurized injection of a volume of vapor media M′ intotargeted airway 280 (see FIG. 9). The pressure and duration of vapordelivery is sufficient to propagate the vapor media M′ to the alveoli288 in the targeted lung region. The inflow of vapor expands thetargeted lung portion but at the same time the condensation of the vaporand its collapse in volume delivers energy without over-expanding thetargeted bronchial tree region 275. In a preferred method andembodiment, the volume of the inflows decreases by at least about 500%upon collapse which releases the heat of vaporization. In more preferredmethods and embodiments, the volume of the inflows decreases by at leastabout 1000% upon collapse and release of the heat of vaporization. Thevapor delivers an amount of energy capable of modifying lung tissue bythe shrinking and collapse of the treated lung tissue 275 to reduce lungvolume. It has been found that the treated airways collapse instantlyupon shrinkage of collagenous tissues in the airway walls which are notsupported by substantial cartilage—which then results in fibrosis andpermanent sealing of the treated airways. The permanent collapse of theairways will be immediate with fibrosis occurring over a period ofseveral weeks. The method encompasses causing multiple desirable tissuemodifications or effects for effective lung volume reduction includingthe shrinkage of lung tissue, the denaturation of lung tissue, thedenaturation of collagen and proteins in airway walls, the damage,ablation or sealing of diseased or normal lung tissue, the occlusion ofairways, the trigger of an immune response and the permanent remodelingof the targeted airways 275.

The method of the invention includes injecting the flow of vapor over asufficiently short interval, for example less than about 30 seconds, tothereby substantially prevent conductive heat transfer to tissuesexternal to the targeted airway. In other words, the heat ofvaporization is deposited very quickly and the thermal relaxation timeof the airway walls prevents substantial heating through the walls. Inmore preferred methods of practicing methods of the invention, theduration of energy delivery is less that about 15 seconds. By themethods described above, referring to FIG. 9, it has been found thatshrinkage and related tissue modifications (described above) extends toalveoli 288 and interalveolar collateral ventilation tissue 290, as wellas bronchioles 292, collagenous lung tissue 294, parenchyma and otherlung tissue (whether diseased lung tissue or normal lung tissue).

The system and method of the invention preferably includes a pressuresensor 185 b in the working end 215 that is coupled to controller 245 tosense excessive pressures in the targeted airways (see FIG. 11). Thepressure sensor 185 b can be set to open a valve, or to adjust anover-pressure valve 264 to automatically release pressure at anyselected level. The sensor 185 b can be of the type manufactured byIntegrated Sensing Systems, Inc., 391 Airport Industrial Drive,Ypsilanti, Mich. 48198. The working end 215 can further carry atemperature sensor (not shown) that is coupled to controller 245 formodulating parameters of media inflows and energy delivery.

In a subsequent step of the method, the termination of the delivery ofvapor media M′ by controller 245 also contemporaneously actuates anotherstep of the method wherein the negative pressure source 270 once againin turned on to extract air from just-treated bronchial tree region 275.The negative pressure source 270 aspirates condensed vapor from theairways and more importantly applies suction forces to the collapsedtissue as in relaxes thermally which assists in permanent remodeling ofthe tissue in the collapsed state. The method includes applying negativepressure to the targeted airways 275 for a selected interval programmedinto controller 245 sufficient for tissue cooling and tissue remodeling,which can range from about 60 seconds to 10 minutes. Thereafter, thecontroller 245 terminates application of negative pressure to thetreated airways 280. Upon a signal from the controller, the physicianthen deflates balloon 220 and withdraws the catheter from the patient tocomplete the procedure.

In another preferred embodiment and method of the invention, referringto FIG. 12, the system 200 can include an optional electrode 295 exposedto the distal end of channel 212 in the catheter for coupling Rf energyto vapor M′. The Rf energy is provided from a suitable Rf source 250that is coupled to electrode 295 by electrical lead 296 a in thecatheter wall. A second electrical lead 296 b is connected to a groundpad 298 as is known in the art. In a method of use, the controller 245actuates the Rf source contemporaneous with the flow of saline vapor M′from working end 215 wherein the conductive saline vapor can beenergized and form a plasma for coupling energy to the surface of thetargeted lung tissue 275. The system thus can couple electrical energyto the tissue in conjunction with the thermal effects of the vapor asdescribed above. In this embodiment, it is preferred to use hypertonicsaline solutions with high sodium chloride concentrations. The method ofcoupling Rf energy to saline vapor as it exits a medical device workingend is further described in co-pending U.S. patent application Ser. No.10/681,625, the entire contents of which are incorporated herein by thisreference.

In another embodiment and method of the invention, referring to FIG. 13,the system 300 can include a secondary pressurized media inflow source305 that is adapted to introduce media or substance 310 (in the form ofat least one of a gas, liquid or particulate) through channel 312 in thehandle into channel 212 to combine with vapor media M′ after it isejected from chamber 225. In a method of the invention, the system thusallows for controlling the average mass temperature of the vapor. In oneembodiment, the additional media 310 comprises a bioinert gas oratomized fluid that is depressurized and introduced into the vapor forthe purpose of reducing the mass average temperature of the injectedmedia to lower than about 100° C. For example, the introduced media 310can be depressurized CO₂, N₂, or O₂ or atomized H₂O. By this means, themass average temperature can be less than 100° C., for example in therange of about 45° C. to 100° C. More preferably, the mass averagetemperature can be in the range of about 60° C. to 95° C. Still morepreferably, the mass average temperature can be in the range of about70° C. to 90° C.

In another embodiment and method of the invention, still referring toFIG. 13, the system 300 can introduce additional media 310 thatcomprises a pharmacologically active substance with the vapor stream,such as any suitable anesthetic, to interact with lung tissue. In asimilar embodiment and method of the invention, the system 300 canintroduce additional media or substance 310 that enhances ablation ordamage of the targeted tissue such as any sclerosing agent. Thesubstance 310 also can be ethyl alcohol which will enhance damage to thetissue targeted for treatment. The substance 310 also can be any toxin,e.g., Botulinum Toxin Type A, that can enhance local tissue damage forlung volume reduction. The substance 310 also can be Tetracycline oranother antibiotic that damages endothelial tissues to promote a strongimmune response resulting in strong adhesions and collagen formation.

In another embodiment, the system of FIG. 13 can introduce a gas orsubstance that comprises an imaging enhancement media as known in theart. The method of the invention further includes the step of imagingthe flow of vapor as it propagates distally in the targeted airway 280(FIG. 9). The system can use hyperpolarized noble gases, for example asknown in the field of using hyperpolarized ³Helium-magnetic resonanceimaging (³He-MRI) to assess the pathophysiology of ventilation andperfusion in patients with lung disease.

FIG. 14 illustrates another system embodiment 400 with handle 402 thatutilizes a resistive element 420 in interior chamber 425 to cause theliquid-to-vapor phase change in the inflowing media M. All other systemcomponents are similar to the previous embodiments and have similarreference numbers. The electrical leads 426 a and 426 b in thisembodiment are coupled to opposing ends of resistive element 420. In oneembodiment, the resistive element 420 comprises a flow permeablestructure such as a syntactic material or open-cell material (FIG. 14).The terms “syntactic”, “open-cell” and “flow permeable” as used hereinrefer to any structure that has substantial porosity for allowing fluidflow therethrough. Such materials have the advantage of providing veryhigh surface areas for conducting heat from an I²R heated material topressurized media flows therein. The syntactic structure is furtherselected to provide an internal pore dimension that causes diffusion andatomization of high pressure inflows, for example of sterile water orsaline. For example, the resistive element 420 can comprise a syntacticmetal, resistive ceramic composite, or include a carbon portion. Suchmaterials are available from ERG Materials and Aerospace Corp., 900Stanford Avenue, Oakland, Calif. 94608 and Poco Graphite(http://www.poco.com). The open-cell material also can be an open cellfoam that is metal plated, a sintered material, a plated entangledfilament material, or any ordered or disordered structure commonly knownin the art.

In the embodiment of FIG. 14, the system further includes a valve system428 and recirculating channel 430 that are adapted for controlling thegeneration and release of vapor from working end 415. In the previousembodiments, the use of Rf energy delivery for vapor generation inchamber 225 (FIG. 8) can cause instantaneous high pressure flows ofvapor. In the system embodiment of FIG. 13, the delivery of energy bymeans of resistive element 420 can require a fraction of a second ormore to produce vapor from high pressure inflows of liquid media M. Forthis reason, the interior chamber 425 includes a recirculation channel430 for a looped flow of vapor—or vapor and water droplets—thatcirculates back to inflow channel or the proximal end 432 of interiorchamber 425. It should be appreciated that the recirculation channel 430can be entirely housed in handle 402 or can circulate back to the source245 or another intermediate chamber. The recirculation channel 430 alsois operatively coupled to a pressure relief valve 262 as describedabove, and can further include a one-way valve indicated at 434. Inoperation of the embodiment, the system is actuated to create vaporwhich can circulate until a switch 435 coupled to controller 245 andvalve 428 is actuated to release vapor M′ from interior chamber 425. Inall other respects, the method of the invention is the same as describedabove.

The schematic view of system 400 in FIG. 14 depicts the valve 428 in thehandle, but the valve can also be located in working end 415 orelsewhere in catheter sleeve 205. Such valve systems can be linked tocontroller 245 by electrical leads in the catheter wall. In anotherembodiment, the valve 428 can be in the working end 415 and therecirculation channel 430 also can extend through the catheter sleeve205 to the working end 415. This system thus assures that high qualityvapor will be ejected from the working end.

The scope of the invention includes the use valve system 428 andrecirculating channel 430 in other embodiments that utilize Rf, lasermicrowave or other energy deliver mechanisms. For example, in an Rfenergy system as in FIG. 8, the valve and recirculating channel 430systems can be used to control slight inconsistencies in vaporgeneration due to varied liquid inflow rates that sometimes results insputtering and incomplete vaporization or inflowing media.

In another embodiment, still referring to FIG. 14, a system thatutilizes a resistive element 420 for vapor generation also well suitedfor a method of the invention that introduces an alternative media or acombination media M into interior chamber 425 that has another lower orhigh heat of vaporization. By this means, the method of the inventionincludes controlling the temperature of the heat of vaporization whichin turn controls the release of energy for ablating tissue. In oneembodiment, for example, the system can vaporize alcohol which willlower the amount of energy delivered per unit volume of vapor as well asenhance the thermal ablation.

In another embodiment similar to that of FIG. 14, the system can use a“compression-decompression” system for generating a therapeutic vapor.In such a system, an external high pressure source infuses heated water(or saline or another liquid) from the external source into an enclosedinterior chamber of the system. The system also includes a valve similarto valve 428 in FIG. 14. Upon opening of the valve, the release ofpressurized fluid will in part release the energy that was exerted onthe fluid in the form of pressure—which will be converted into theenergy required to vaporize the heated fluid. This type of system hasthe advantage of not requiring a thermal energy source with sufficientcapacity for vaporizing needed volumes of vapor. Instead, apressurization mechanism combined with a less robust thermal energydelivery system can be used to produce the required volume of vapor.Such a source would typically be external to the handle of the catheter.

In another method of the invention, a catheter system can be used forcryotherapy of the lung, wherein thermal cooling or freezing methodsknown in the art could promote lung volume reduction via the woundhealing response to such cryotherapy. In one embodiment, a high pressureliquid nitrogen source external to the catheter comprises a source forcold nitrogen gas. The handle of the catheter includes a valve forreleasing the cryofluid which would expand the targeted lung region.Introduction of such nitrogen gas from the working end 215 of thecatheter would result in instantaneous freezing of surface tissues ofthe targeted airway 275 (cf. FIG. 9). Due to the nature of ice crystalformation in tissue, the affected cells would burst due to a physicalexpansion in size. The damaged lung tissue would then remodel as itprogresses through the normal wound healing response. The treated airwayalso could be blocked with a plug to help prevent the airway fromexpanding until fibrosis has occurred over a period of several weeks.Other liquids also can be used in a cryotherapy, such as oxygen andcarbon dioxide.

Although the invention is described to treating a patient's lung forlung volume reduction, the scope of the invention includes applyingenergy to lung tissue for other disorders such as asthma and the like.

The invention as described in detail above utilizes Rf energy deliverymeans or a resistive heating means. The scope of the invention includesapplying energy from other suitable sources such as coherent ofbroadband light energy, microwave, ultrasound or magnetic inductiveheating of liquid media to generate suitable vapor as are known to thoseskilled in the art.

Although particular embodiments of the present invention have beendescribed above in detail, it will be understood that this descriptionis merely for purposes of illustration and the above description of theinvention is not exhaustive. Specific features of the invention areshown in some drawings and not in others, and this is for convenienceonly and any feature may be combined with another in accordance with theinvention. A number of variations and alternatives will be apparent toone having ordinary skills in the art. Such alternatives and variationsare intended to be included within the scope of the claims. Particularfeatures that are presented in dependent claims can be combined and fallwithin the scope of the invention. The invention also encompassesembodiments as if dependent claims were alternatively written in amultiple dependent claim format with reference to other independentclaims.

1. A method of treating a disorder of a lung comprising: generating aflow of vapor; introducing the flow of vapor into a targeted airway ofthe lung at a pressure sufficient to extend the flow of vapor toextremities of the targeted airway; delivering thermal energy to thelung tissue via a vapor-to-liquid phase transition of the vapor; andmodifying the lung tissue to treat the disorder.
 2. The method of claim1 further comprising generating the flow of vapor by at least one ofresistive heating means, radiofrequency (Rf) energy means, microwaveenergy means, photonic energy means, magnetic induction energy means,compression and decompression means, and ultrasonic energy means.
 3. Themethod of claim 1, further comprising controlling at least one of thepressure of the flow of vapor, the volume of the flow of vapor and theduration of the flow of vapor.
 4. The method of claim 1, furthercomprising controlling the temperature of the heat of vaporization ofthe vapor.
 5. The method of claim 1 wherein modifying lung tissueincludes at least one of shrinkage, denaturation, damage, ablation,sealing, occlusion, an immune response or remodeling of lung tissue. 6.The method of claim 5 wherein the lung tissue includes at least one ofbronchi, bronchioles, alveoli, parenchyma, diseased lung tissue, normallung tissue, collagenous lung tissue and interalveolar collateralventilation tissue.
 7. The method of claim 1 wherein introducing theflow of vapor includes introducing the flow over a sufficiently shortinterval to substantially prevent conductive heat transfer to bodystructure external to a targeted airway.
 8. The method of claim 1including generating the vapor from at least one of water, saline andalcohol.
 9. The method of claim 1 wherein introducing the flow of vaporincludes introducing at least one substance with the vapor.
 10. Themethod of claim 9 wherein the substance is an imaging enhancing media.11. The method of claim 1 including introducing at least onepharmacologically active agent with the vapor.
 12. The method of claim11 wherein the pharmacologically active agent is at least on one of ananesthetic, an antibiotic, a toxin and a sclerosing agent.
 13. Themethod of claim 1 further comprising imaging the flow of vapor.
 14. Themethod of claim 1 wherein introducing the flow of vapor is preceded byexpanding an expansion structure in a proximal portion of a targetedairway for controlling the direction of the flow of vapor.
 15. Themethod of claim 14 wherein expanding the expansion structure includesevacuating air from the airway distal to the expansion structure. 16.The method of claim 1 further comprising the step of applying negativepressure to the targeted airway after terminating the flow of vapor. 17.The method of claim 16 wherein applying negative pressure is performedfor an interval sufficient for at least one of tissue cooling and tissueremodeling.
 18. The method of claim 1 wherein the heat of vaporizationof the vapor is above about 45′ C.
 19. The method of claim 1 furthercomprising coupling electrical energy to the flow of vapor.
 20. Themethod of claim 1 wherein the disorder of the lung comprises emphysema.21. The method of claim 1 further comprising expanding an occlusionballoon in a proximal portion of the targeted airway to direct the flowof vapor toward the extremities of the targeted airway.
 22. A method oftreating a disorder of a lung comprising: generating a flow of vapor;expanding an expansion structure in a proximal portion of a targetedairway to occlude the airway; introducing the flow of vapor into thelung distal to the expansion structure; delivering thermal energy to thelung tissue via a vapor-to-liquid phase transition of the vapor; andmodifying the lung tissue to treat the disorder.
 23. The method of claim22 wherein the expansion structure directs the flow of vapor towardextremities of the targeted airway.
 24. The method of claim 22 whereinintroducing the flow of vapor includes introducing the flow over asufficiently short interval to substantially prevent, conductive heattransfer to body structure external to a targeted airway.
 25. The methodof claim 22 wherein modifying lung tissue includes at least one ofshrinkage, denaturation, damage, ablation, sealing, occlusion, an immuneresponse or remodeling of lung tissue.
 26. The method of claim 22wherein the disorder of the lung comprises emphysema.
 27. The method ofclaim 22 wherein the lung tissue includes at least one of bronchi,bronchioles, alveoli, parenchyma, diseased lung tissue, normal lungtissue, collagenous lung tissue and interalveolar collateral ventilationtissue.